“Book-trade catalogues, generally referred to as book fair catalogues, offer a unique overview of German – and in many respects European – book production over a period of nearly 300 years (1594-1860). This form of information, originally intended for the contemporary book trade, today forms an important and comprehensive historical bibliography of the period.
Developed in the 16th century, the book fair catalogues for the Spring or Easter and Autumn or Michaelmas Fairs provided the widest possible overview of the books on offer during this period. Only when other sources of information began to take their place did they cease publication in 1860.
The digitisation is based on the microfilming of the book fair catalogues from 1594 onwards. To bring the various and astonishingly scattered holdings of different libraries together and create and almost complete run was a major editorial achievement. There were only a few years during the Thirty Years’ War when no catalogues are known to have appeared.” http://www.olmsonline.de/en/kollektionen/messkataloge/